Thread (23 messages) 23 messages, 7 authors, 2024-05-30

Re: [PATCHv6 9/9] man2: Add uretprobe syscall page

From: Jiri Olsa <hidden>
Date: 2024-05-21 11:49:03
Also in: bpf, linux-api, linux-man, lkml

On Tue, May 21, 2024 at 01:36:25PM +0200, Alejandro Colomar wrote:
Hi Jiri,

On Tue, May 21, 2024 at 12:48:25PM GMT, Jiri Olsa wrote:
quoted
Adding man page for new uretprobe syscall.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 man2/uretprobe.2 | 50 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 man2/uretprobe.2
diff --git a/man2/uretprobe.2 b/man2/uretprobe.2
new file mode 100644
index 000000000000..690fe3b1a44f
--- /dev/null
+++ b/man2/uretprobe.2
@@ -0,0 +1,50 @@
+.\" Copyright (C) 2024, Jiri Olsa <jolsa@kernel.org>
+.\"
+.\" SPDX-License-Identifier: Linux-man-pages-copyleft
+.\"
+.TH uretprobe 2 (date) "Linux man-pages (unreleased)"
+.SH NAME
+uretprobe \- execute pending return uprobes
+.SH SYNOPSIS
+.nf
+.B int uretprobe(void)
+.fi
What header file provides this system call?
there's no header, it's used/called only by user space trampoline
provided by kernel, it's not expected to be called by user
quoted
+.SH DESCRIPTION
+The
+.BR uretprobe ()
+syscall is an alternative to breakpoint instructions for
+triggering return uprobe consumers.
+.P
+Calls to
+.BR uretprobe ()
+suscall are only made from the user-space trampoline provided by the kernel.
s/suscall/system call/
ugh leftover sry
quoted
+Calls from any other place result in a
+.BR SIGILL .
Maybe add an ERRORS section?
quoted
+
We don't use blank lines; it causes a groff(1) warning, and other
problems.  Instead, use '.P'.
quoted
+.SH RETURN VALUE
+The
+.BR uretprobe ()
+syscall return value is architecture-specific.
+
.P
quoted
+.SH VERSIONS
+This syscall is not specified in POSIX,
Redundant with "STANDARDS: None.".
quoted
+and details of its behavior vary across systems.
Keep this.
ok
quoted
+.SH STANDARDS
+None.
+.SH HISTORY
+TBD
+.SH NOTES
+The
+.BR uretprobe ()
+syscall was initially introduced for the x86_64 architecture where it was shown
+to be faster than breakpoint traps. It might be extended to other architectures.
Please use semantic newlines.

$ MANWIDTH=72 man man-pages | sed -n '/Use semantic newlines/,/^$/p'
   Use semantic newlines
     In the source of a manual page, new sentences should be started on
     new lines, long sentences should be split  into  lines  at  clause
     breaks  (commas,  semicolons, colons, and so on), and long clauses
     should be split at phrase boundaries.  This convention,  sometimes
     known as "semantic newlines", makes it easier to see the effect of
     patches, which often operate at the level of individual sentences,
     clauses, or phrases.
ok

thanks,
jirka
quoted
+.P
+The
+.BR uretprobe ()
+syscall exists only to allow the invocation of return uprobe consumers.
s/syscall/system call/
quoted
+It should
+.B never
+be called directly.
+Details of the arguments (if any) passed to
+.BR uretprobe ()
+and the return value are architecture-specific.
-- 
2.44.0
Have a lovely day!
Alex

-- 
<https://www.alejandro-colomar.es/>
  
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